Ionic bonds are formed from the attraction of oppositely charged ions in a chemical compound
Answer: physical
Explanation: freezing and melting are physical changes.
Answer:
True
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer:
compound
Explanation:
because now there are one together
Answer:

Explanation:
Assuming that all caculations are at normal pressure and -1.72°C :

Where
is the number of moles of hydrogen
is the mass of hydrogen
is the density of hydrogen